Mechanical movement



R. LOEB.

MECHANICAL MOVEMENT.

APPLlCATlON FILED JAN.28. 1921.

1,41 1 ,855. Patented p 4, 1922.

UNITED STATES RUDOIJF LOEIB, OF JENKINTOWN, PENNSYLVANIA.

MECHANICAL MOVEMENT.

Specification of Letters Patent.

Patented Apr. 4:, 1922.

Application filed. January 28, 1921. Serial No. 440,718.

To (ZZZ whom it may concern:

Be it known that L'PtUDOLF Lone, a citizen of the United States, residing in Jenkintown, Montgomery County, Pennsylvania, have invented certain Improvements in a Mechanical Movement, of which the following is a specification.

ivlyinvention relates to certain improvements in-mechanism for converting a rotary motion into a reciprocating motion, and one object of my invention is to provide means for imparting a limited forward I110- tion to a, device and to retard the return movement. A further object of my invention is to impart a quick forward motion to a reciprocating deviceand to return the device at a comparatively slow rateofspeed. The invention can be used for a number of purposes, and one for which the invention is particularly adapted is the operation of a reciprocating cutting knife in whichthe 1 01- ward cutting movement will be rapid, while the return movement will be retarded.

In the accompanying drawings Fig. 1 is aside view of a deviceillustratinn my improved mechanical movement;

Fig. 2 is a sectional view on the line 22, Fig. 1;

Figs. 3, 1 and 5 are diagrammatic views; and

Fig. 6 is a diagrammatic sectional view of a fabric cutting machine illustrating one application of my invention.

In the fabric cutting machine illustrated in Fig. 6. ais the fabric which is fed between two rolls 7) and 0. In. the roll (2 is a reciprocating knife (Z which cuts the fabric while the knife is passing over a limited portion of the surface of the roll Z), from the point a: to the point at. The knife returned to its original position while the roll 0 is completing its revolution.

By the use of my inventionthe knife r5 will he moved rapidly across the roll 6 and in contact with the lower roll 7).

The return movement of the knife will be retarded and will take place while the roll is completing one full revolution.

Referring now to Fig. 1, 1 is a bearing. 2 is a power shaft extending e-ccentrically through the bearing and secured to this power shaft is an arm 3 having a roll 4;. projecting into a recess 5 of a sprocket wheel 6 in the present instance. The wheel is loosely mounted on the bearing 1, Fig. 2;

Engaging with this sprocket wheel 18 a chain 7. which may be attached to the knife frame of the device shown in Fig. (3 or to any other mechanism which requires the peculia. n iovement described above.

Secured to the sprocketwhecl (3 15 an arm 8 to which is attachedaspring 9, or a weight,

Referring to Fig. 1, when the arm 3 moved in the direction of its arrow the roll A; is in contact with the shoulder 11 on the sprocket wheel and the wheel is moved in the direction of its arrow by the arm, owing to the wheel. being eccentricallv niounte zl in respect to the shaft .2. hen the arm reaches a point indicated in. Fig. 3 the shoulder is moved away from it, releasing the sprocket wheel and as the spring 9 has been lnought under tension due to the rotation of the wheelpthe springwill tendto return the same to its first position, F l, but the roll is so proportioned to the eccentric wall 1.0 of the recess 5 that it will bear upon the wall with sufficient friction to re tard the return movement due to the tension on the spring so that instead of the sprorket wheel rapidly returning. it will return slowly due to the frictional contact of the roll The eccentric surface of the wheel is so proportioned that the roll lwill be in frictional contact with the surface until it reaches a point slightly in advance of the shoulder 11 and from this point to the shoulder the roll is clear of the surface and the spring 9 will complete the return of the knife to its first position and the shoulder will come in contact with the roll. As the chain 7 meshes with the teeth of the sprocket wheel it will be seen that any device attached to the chain will have a quick forward movement and a retarded return movement, whether the device he a cutting knife or other mechanism to which my mechanical movement can be applied.

While I have shown my invention as ap plied to a sprocket wheel, itwill be understood that the shouldered cam element may be mounted independently of the sprocket wheel and connected thereto and in place of the sprocket wheel a crank pin may be mounted on the element and connected to the device to be operated through a rod or other mechanism, and in some instances the cam element 6 may be secured to a shaft through Which the motion may be imparted.

I claim:

1. The combination in an apparatus for converting a rotary motion into a recipr0- eating motion, of a reciprocable member and a rotating driving member including means for imparting a quick forward movement to said mechanism, a portion of said driving mechanism and the reciprocable member coacting to retard the return movement of the latter.

shift; a driven element mounted 'on the bearing and having a shouldered portion and a cam, said arm being arranged to contact with the shoulder to turn the element for a portion of its revolution; and means for returnin the element when released from the contro of thearm, the arm being positioned to frictionally engage the cam to retard its return movement.

4. In a mechanical movement the combination ofa bearing; a wheel loosely mounted thereon and formed with a cam terminatin in a shoulder; a shaft eccentrically mounted in the bearing and having an arm; a roll on the arm positioned to coact with the shoulder and cam; and a spring for returnin the wheel to its normal position the arm fieing positioned to engage the shoulder for a portion of a revolution and thereafter disengage the same to permit the spring to return the wheel to its original osition, theroll on the arm bearing upon t e cam to retard its return movementQ 5. The combintaion of a bearing; a sprocket wheel mounted thereon and having a cam terminating in a shoulder; a shaft eccentrically mounted in the bearing; an arm on the shaft; a roll on the arm positioned to frictionally engage the cam and arranged to bear against the shoulder; a spring attached to the sprocket wheel for returning the same to itsnormal position; and a chain engaging the sprocket wheel and attached to a devlce to be operated; the arm beingmounted to engage the shoulder to turn the sprocket Wheel a portion of a revolution then disengage said shoulder to allow the sprocket wheel to be returned by the spring, the roll being positioned to bear against the cam and retard thereturn move. ment of the sprocket wheel.

RUDOLF LOEB. 

